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emp1表結構與emp相同﹐只是資料多一點
1.
以sysdba:
SQL> grant query rewrite to scott;
順利授權.
SQL> grant create any index to scott;
順利授權.
2.
以scott進入
SQL> alter session set query_rewrite_enabled=true;
已更改階段作業.
SQL> alter session set query_rewrite_integrity=trusted;
已更改階段作業.
SQL> create index I_JOB_EMP1 on EMP1(INSTR(JOB,'AG'));
已建立索引.
SQL> analyze table emp1 compute statistics;
已分析表格.
SQL> set autotrace traceonly explain
SQL> select empno,ename,job
2 from emp1
3 where instr(job,'AG')<>0;
執行計畫
----------------------------------------------------------
0 SELECT STATEMENT Optimizer=CHOOSE (Cost=2 Card=88 Bytes=1320
)
1 0 TABLE ACCESS (FULL) OF 'EMP1' (Cost=2 Card=88 Bytes=1320)
SQL> spool off |
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